The short-term and long-term relationship between delirium and cognitive trajectory in older surgical patients

The Geriatric Patient: Frailty, Prehabilitation, and Postoperative Delirium

Historically and for ease of classification, the geriatric patient has received a chronologic definition of a person 65 years and older. Chronologic age remains an independent risk of postoperative complications and adverse surgical outcomes. Frailty is an expression of an individual's biological age and as such a more reliable determination of their vulnerabilities or resilience to stress. The concept of prehabilitation has shown promise as a proactive approach to optimize a patient's functional, cognitive, nutritional, and emotional in preparation for surgical interventions. Postoperative delirium is the most common neuropsychological complication after surgery.

The Relationship between Delirium and Dementia

Delirium and dementia are common causes of cognitive impairment in older adults. They are distinct but interrelated. Delirium, an acute confusional state, has been linked to the chronic and progressive loss of cognitive ability seen in dementia. Individuals with dementia are at higher risk for delirium, and delirium itself is a risk factor for incident dementia. Additionally, delirium in individuals with dementia can hasten underlying cognitive decline. In this review, we summarize recent literature linking these conditions, including epidemiological, clinicopathological, neuroimaging, biomarker, and experimental evidence supporting the intersection between these conditions. Strategies for evaluation and diagnosis that focus on distinguishing delirium from dementia in clinical settings and recommendations for delirium prevention interventions for patients with dementia are presented. We also discuss studies that provide evidence that delirium may be a modifiable risk factor for dementia and consider the impact of delirium prevention interventions on long-term outcomes.

Prevalence of neurocognitive disorders 5 years after elective orthopaedic surgery

BACKGROUND

Peri-operative neurocognitive disorders are one of the most common complications affecting older adults after anaesthesia and surgery. It is not clear how exposure to surgery and anaesthesia contributes to the prevalence of long-term neurocognitive disorders. This study aimed to report the prevalence of neurocognitive disorders, and explore pre-operative factors associated with neurocognitive disorders 5 years after elective orthopaedic surgery.

METHODS

A prospective, 5-year longitudinal, cohort study was performed recruiting patients (aged ≥ 60 y) undergoing elective orthopaedic surgery and a contemporaneous non-surgical control group. Neurocognitive disorder was evaluated and classified at baseline and 5-year review incorporating: self- and informant-reported cognition; functional participation; and performance on neuropsychological tests.

RESULTS

Recruitment at 5-year follow-up included 195 patients and 21 control participants. In the patient cohort the prevalence of neurocognitive disorder was 38.1% (n = 75), with 61 (30.1%) meeting the criteria for mild neurocognitive disorder and 14 (7.1%) for major neurocognitive disorder. At 5-year follow-up, 121 (61.4%) patients were classified with a neurocognitive disorder, with 88 (44.7%) characterised with mild neurocognitive disorder and 33 (16.8%) with major neurocognitive disorder. Age (odds ratio (95%CI) 1.07 (1.02-1.13); p = 0.01) and baseline cognitive impairment (odds ratio (95%CI) 2.1 (1.06-4.15); p = 0.03) were significant predictors of neurocognitive disorder 5 years after surgery.

CONCLUSION

More than half of older adult patients had some form of neurocognitive disorder 5 years after elective orthopaedic surgery. Surgery and anaesthesia may be associated with the trajectory of cognitive decline in at-risk older adults, including those with pre-operative cognitive impairment. Cognitive screening should be factored into pre-operative assessments of older adults to inform subsequent care.

Long-Term Impact of Delirium on the Risk of Dementia in Hospitalized Older Patients: A Real-World Multicenter Study

BACKGROUND

The association between delirium and dementia has been suggested, but mostly in the postoperative setting. This study aims to explore this relationship in a broader inpatient population, leveraging extensive real-world data to provide a more generalized understanding.

METHODS

In this retrospective cohort study, electronic health records of 11,970,475 hospitalized patients aged over 60 from nine institutions in South Korea were analyzed. Patients with and without delirium were identified, and propensity score matching (PSM) was used to create comparable groups. A 10-year longitudinal analysis was conducted using the Cox proportional hazards model, which calculated the hazard ratio (HR) and 95% confidence interval (CI). Additionally, a meta-analysis was performed, aggregating results from all nine medical institutions. Lastly, we conducted various subgroup and sensitivity analyses to demonstrate the consistency of our study results across diverse conditions.

RESULTS

After 1:1 PSM, a total of 47,306 patients were matched in both the delirium and nondelirium groups. Both groups had a median age group of 75-79 years, with 43.1% being female. The delirium group showed a significantly higher risk of all dementia compared with the nondelirium group (HR: 2.70 [95% CI: 2.27-3.20]). The incidence risk for different types of dementia was also notably higher in the delirium group (all dementia or mild cognitive impairment, HR: 2.46 [95% CI: 2.10-2.88]; Alzheimer's disease, HR: 2.74 [95% CI: 2.40-3.13]; vascular dementia, HR: 2.55 [95% CI: 2.07-3.13]). This pattern was consistent across all subgroup and sensitivity analyses.

CONCLUSIONS

Delirium significantly increases the risk of onset for all types of dementia. These findings highlight the importance of early detection of delirium and prompt intervention. Further research studies are warranted to investigate the mechanisms linking delirium and dementia.

Incidence and related risk factors for postoperative delirium following revision total knee arthroplasty: a retrospective nationwide inpatient sample database study

BACKGROUND

Postoperative delirium (POD) is a common surgical complication. However, the incidence and risk factors associated with postoperative delirium after revision total knee arthroplasty (rTKA) have not been comprehensively explored through extensive national databases.

METHODS

Utilizing the National Inpatient Sample (NIS), the largest comprehensive U.S. hospital healthcare database, we undertook a retrospective investigation involving 127,400 patients who underwent rTKA between 2010 and 2019. We assessed various aspects, including patient demographics, hospital characteristics, pre-existing medical conditions, and perioperative complications.

RESULTS

The overall incidence of postoperative delirium (POD) in patients undergoing rTKA between 2010 and 2019 was 0.97%. The highest incidence rate of 1.31% was recorded in 2013. Notably, this patient cohort demonstrated advanced age, increased burden of co-morbidities, prolonged hospital stays, increased hospitalization costs, and elevated in-hospital mortality rates (P < 0.001). Moreover, non-elective admissions, non-private insurance payments, and a preference for teaching hospitals were commonly observed among these patients. During their hospitalization, individuals who developed delirium subsequent to rTKA were more prone to experiencing certain perioperative complications. These complications encompassed medical issues like acute myocardial infarction, continuous invasive mechanical ventilation, postoperative shock, sepsis, stroke and other medical problems. Additionally, surgical complications including hemorrhage / seroma / hematoma, irrigation and debridement, prosthetic joint infection, periprosthetic fracture, and wound dehiscence / nonunion were noted. Several risk factors were found to be linked with the development of POD. These included advanced age (≥ 75 years), alcohol abuse, coagulation disorders, congestive heart failure, depression, fluid and electrolyte imbalances, and more. Conversely, female sex, having private insurance, and undergoing elective hospitalization emerged as protective factors against POD.

CONCLUSION

Our findings suggest that the general prevalence of POD in rTKA is relatively low according to NIS. There was a significant connection between the POD of rTKA and advanced age, prolonged length of stay (LOS), more in-patients' costs, higher in-hospital mortality rate, increased comorbidities, postoperative medical complications and postoperative surgical complications. This study helps to understand the risk factors associated with POD to improve poor outcomes.

Histidine-Tryptophan-Ketoglutarate Cardioplegia Yields Different Results in Aortic Valve Surgery Depending on Patient Gender: A Pilot Study

BACKGROUND

Histidine-tryptophan-ketoglutarate (HTK) cardioplegia induces cardiac arrest through membrane hyperpolarization. Aortic valve pathology leads to pathophysiological changes in left ventricular vascularization that may prevent adequate cardioplegic distribution. The objective of the study was to ascertain whether the use of Bretschneider cardioplegia in aortic valve surgery yields different outcomes for male and female patients.

METHODOLOGY

Our study compares the perioperative data of 300 adult patients who underwent aortic valve replacement between June 2023 and June 2024 at the Emergency Cardiac Disease and Transplant Institute, Tîrgu Mures, Romania. Concomitant procedures, age under 18 years, retrograde or combined cardioplegia, and emergency surgery were excluded. The main outcome was operative mortality, and secondary outcomes were postoperative complications and paraclinical data such as ejection fraction and cardiac enzymes.

RESULTS

Male patients comprised 190 (62%) of the sample. The most common age group was 61-70 years in both groups. The mortality rate was 6 (5.4%) for women compared to 9 (4.7%) for men. Preoperative left ventricular ejection fraction was the primary covariate determining 30-day postoperative mortality. Left ventricular ejection fraction decreased by 2.2% in men and 1.1% in women 30 days after surgery.

CONCLUSIONS

The myocardial adaptation to aortic valve pathology exhibits gender-specific differences. However, the utilization of HTK cardioplegia obviates this disparity.

Relationship between cortical brain atrophy, delirium, and long-term cognitive decline in older surgical patients

In older patients, delirium after surgery is associated with long-term cognitive decline (LTCD). The neural substrates of this association are unclear. Neurodegenerative changes associated with dementia are possible contributors. We investigated the relationship between brain atrophy rates in Alzheimer's disease (AD) and cognitive aging signature regions from magnetic resonance imaging before and one year after surgery, LTCD assessed by the general cognitive performance (GCP) score over 6 years post-operatively, and delirium in 117 elective surgery patients without dementia (mean age = 76). The annual change in cortical thickness was 0.2(1.7) % (AD-signature p = 0.09) and 0.4(1.7) % (aging-signature p = 0.01). Greater atrophy was associated with LTCD (AD-signature: beta(CI) = 0.24(0.06-0.42) points of GCP/mm of cortical thickness; p < 0.01, aging-signature: beta(CI) = 0.55(0.07-1.03); p = 0.03). Atrophy rates were not significantly different between participants with and without delirium. We found an interaction with delirium severity in the association between atrophy and LTCD (AD-signature: beta(CI) = 0.04(0.00-0.08), p = 0.04; aging-signature: beta(CI) = 0.08(0.03-0.12), p < 0.01). The rate of cortical atrophy and severity of delirium are independent, synergistic factors determining postoperative cognitive decline in the elderly.

Integrated Multi-Omics Analysis of Cerebrospinal Fluid in Postoperative Delirium

Preoperative risk biomarkers for delirium may aid in identifying high-risk patients and developing intervention therapies, which would minimize the health and economic burden of postoperative delirium. Previous studies have typically used single omics approaches to identify such biomarkers. Preoperative cerebrospinal fluid (CSF) from the Healthier Postoperative Recovery study of adults ≥ 63 years old undergoing elective major orthopedic surgery was used in a matched pair delirium case-no delirium control design. We performed metabolomics and lipidomics, which were combined with our previously reported proteomics results on the same samples. Differential expression, clustering, classification, and systems biology analyses were applied to individual and combined omics datasets. Probabilistic graph models were used to identify an integrated multi-omics interaction network, which included clusters of heterogeneous omics interactions among lipids, metabolites, and proteins. The combined multi-omics signature of 25 molecules attained an AUC of 0.96 [95% CI: 0.85-1.00], showing improvement over individual omics-based classification. We conclude that multi-omics integration of preoperative CSF identifies potential risk markers for delirium and generates new insights into the complex pathways associated with delirium. With future validation, this hypotheses-generating study may serve to build robust biomarkers for delirium and improve our understanding of its pathophysiology.

Summary of the Clinical Evidence for Non-Pharmacological Management of Postoperative Delirium in Adults: An Evidence Synthesis

Objective

To retrieve, evaluate, and summarise the clinical evidence for non-pharmacological interventions in adult postoperative delirium (POD), encompassing the preoperative, intraoperative, and postoperative phases.

Methods

The methods included conducting searches on UpToDate Clinical Consultants, the Scottish Intercollegiate Guidelines Network, the National Institute for Health and Care Excellence, the Registered Nurses' Association of Ontario, BMJ Best Practice, the Cochrane Library, Web of Science, PubMed, China National Knowledge Infrastructure, Wanfang, VIP, and the Chinese Biomedical Literature Service System. Clinical practice guidelines, clinical decision-making, evidence summaries, evidence synthesis, expert consensus, systematic reviews, and meta-analyses on non-pharmacological interventions for adult POD were examined, and the search period spanned between the establishment of each database and 30 October 2023.

Results

A total of 17 documents were included, comprising three guidelines, one expert consensus, one clinical decision-making article, four evidence summaries, three systematic reviews, and five meta-analyses. These documents primarily focused on the following three aspects: preoperative, intraoperative, and postoperative care. In total, 30 "best evidence" instances were compiled.

Conclusion

Considering the complexity and potential harm of adult POD, an accurate and timely evaluation of high-risk factors, alongside effective medical nursing strategies, is vital in its prevention and treatment. Non-pharmacological interventions remain the preferred choice for preventing and treating POD. Medical institutions should establish standardised processes for non-pharmacological intervention in adult POD, based on evidence-based medicine, to enhance the level of clinical care in this field.

Electroencephalography-Guided Anesthesia and Delirium in Older Adults After Cardiac Surgery: The ENGAGES-Canada Randomized Clinical Trial

Importance

Intraoperative electroencephalogram (EEG) waveform suppression, suggesting excessive general anesthesia, has been associated with postoperative delirium.

Objective

To assess whether EEG-guided anesthesia decreases the incidence of delirium after cardiac surgery.

Design, Setting, and Participants

Randomized, parallel-group clinical trial of 1140 adults 60 years or older undergoing cardiac surgery at 4 Canadian hospitals. Recruitment was from December 2016 to February 2022, with follow-up until February 2023.

Interventions

Patients were randomized in a 1:1 ratio (stratified by hospital) to receive EEG-guided anesthesia (n = 567) or usual care (n = 573). Patients and those assessing outcomes were blinded to group assignment.

Main Outcomes and Measures

The primary outcome was delirium during postoperative days 1 through 5. Intraoperative measures included anesthetic concentration and EEG suppression time. Secondary outcomes included intensive care and hospital length of stay. Serious adverse events included intraoperative awareness, medical complications, and 30-day mortality.

Results

Of 1140 randomized patients (median [IQR] age, 70 [65-75] years; 282 [24.7%] women), 1131 (99.2%) were assessed for the primary outcome. Delirium during postoperative days 1 to 5 occurred in 102 of 562 patients (18.15%) in the EEG-guided group and 103 of 569 patients (18.10%) in the usual care group (difference, 0.05% [95% CI, -4.57% to 4.67%]). In the EEG-guided group compared with the usual care group, the median volatile anesthetic minimum alveolar concentration was 0.14 (95% CI, 0.15 to 0.13) lower (0.66 vs 0.80) and there was a 7.7-minute (95% CI, 10.6 to 4.7) decrease in the median total time spent with EEG suppression (4.0 vs 11.7 min). There were no significant differences between groups in median length of intensive care unit (difference, 0 days [95% CI, -0.31 to 0.31]) or hospital stay (difference, 0 days [95% CI, -0.94 to 0.94]). No patients reported intraoperative awareness. Medical complications occurred in 64 of 567 patients (11.3%) in the EEG-guided group and 73 of 573 (12.7%) in the usual care group. Thirty-day mortality occurred in 8 of 567 patients (1.4%) in the EEG-guided group and 13 of 573 (2.3%) in the usual care group.

Conclusions and Relevance

Among older adults undergoing cardiac surgery, EEG-guided anesthetic administration to minimize EEG suppression, compared with usual care, did not decrease the incidence of postoperative delirium. This finding does not support EEG-guided anesthesia for this indication.

Trial Registration

ClinicalTrials.gov Identifier: NCT02692300.

Predictiveness of preoperative laboratory values for postoperative delirium

Background

Postoperative delirium (POD) is a common postoperative complication, especially in patients over 60 years, with an incidence ranging from 15% to 50%. In most cases, POD manifests in the first 5 days after surgery. Multiple contributing risk factors for POD have been detected. Besides the predisposing factors such as higher age, cognitive impairment, high blood pressure, atrial fibrillation, and past stroke, pathophysiological mechanisms like neuroinflammation are also considered as contributing factors.

Methods

In a subanalysis of the "PRe- Operative  Prediction of postoperative  DElirium by appropriate  SCreening" (PROPDESC) study, the preoperative laboratory values of sodium, potassium, total protein, hemoglobin concentration (Hgb), and white blood cells as well as the biomarkers creatinine, HbA1c, NT-pro-BNP, high sensitive Troponin T (hsTnT), and C-reactive protein (CRP) were assessed to investigate a possible relationship to the occurrence of POD.

Results

After correction for age, physical status classification, surgery risk after Johns Hopkins, and operative discipline (cardiac surgery vs. noncardiac surgery), male patients with a Hgb <13 g/dL had significantly higher odds for POD (p = 0.025). Furthermore, patients with CRP ≥ 10 mg/L, HbA1c value ≥ 8.5% as well as patients with hypernatraemia (>145 mmol/L) presented significantly higher odds to develop POD (p = 0.011, p < 0.001, and p = 0.021, respectively). A raised (>14-52 ng/L) or high (>52 ng/L) hsTnT value was also associated with a significantly higher chance for POD compared to the patient group with hsTnT <14 ng/L (p < 0.001 and p = 0.016, respectively).

Conclusions

Preoperative Hgb, CRP, HbA1c, sodium, and hsTnT could be used to complement and refine the preoperative screening for patients at risk for POD. Further studies should track these correlations to investigate the potential of targeted POD protection and enabling hospital staff to initiate POD-preventing measures in time.

In-Hospital Delirium and Disability and Cognitive Impairment After COVID-19 Hospitalization

Importance

Older adults who are hospitalized for COVID-19 are at risk of delirium. Little is known about the association of in-hospital delirium with functional and cognitive outcomes among older adults who have survived a COVID-19 hospitalization.

Objective

To evaluate the association of delirium with functional disability and cognitive impairment over the 6 months after discharge among older adults hospitalized with COVID-19.

Design, Setting, and Participants

This prospective cohort study involved patients aged 60 years or older who were hospitalized with COVID-19 between June 18, 2020, and June 30, 2021, at 5 hospitals in a major tertiary care system in the US. Follow-up occurred through January 11, 2022. Data analysis was performed from December 2022 to February 2024.

Exposure

Delirium during the COVID-19 hospitalization was assessed using the Chart-based Delirium Identification Instrument (CHART-DEL) and CHART-DEL-ICU.

Main Outcomes and Measures

Primary outcomes were disability in 15 functional activities and the presence of cognitive impairment (defined as Montreal Cognitive Assessment score <22) at 1, 3, and 6 months after hospital discharge. The associations of in-hospital delirium with functional disability and cognitive impairment were evaluated using zero-inflated negative binominal and logistic regression models, respectively, with adjustment for age, month of follow-up, and baseline (before COVID-19) measures of the respective outcome.

Results

The cohort included 311 older adults (mean [SD] age, 71.3 [8.5] years; 163 female [52.4%]) who survived COVID-19 hospitalization. In the functional disability sample of 311 participants, 49 participants (15.8%) experienced in-hospital delirium. In the cognition sample of 271 participants, 31 (11.4%) experienced in-hospital delirium. In-hospital delirium was associated with both increased functional disability (rate ratio, 1.32; 95% CI, 1.05-1.66) and increased cognitive impairment (odds ratio, 2.48; 95% CI, 1.38-4.82) over the 6 months after discharge from the COVID-19 hospitalization.

Conclusions and Relevance

In this cohort study of 311 hospitalized older adults with COVID-19, in-hospital delirium was associated with increased functional disability and cognitive impairment over the 6 months following discharge. Older survivors of a COVID-19 hospitalization who experience in-hospital delirium should be assessed for disability and cognitive impairment during postdischarge follow-up.

Effects of different anesthetic regimens on postoperative cognitive function of elderly patients undergoing thoracic surgery: a double-blinded randomized controlled trial

OBJECTIVE

Postoperative cognitive dysfunction (POCD) is a serious surgical complication. We assessed the different POCD incidences between anesthesia using sevoflurane and sevoflurane combined with dexmedetomidine, with propofol-based sedation in elderly patients who underwent a thoracic surgical procedure.

METHODS

A total of 90 patients aged 65 to 80 years old who underwent a thoracic surgical procedure at our hospital and 15 nonsurgical participants as controls, were enrolled in this study. Patients were divided in a randomized 1:1:1 ratio into 3 groups. All participants were randomized into a trial with three anesthesia groups (P, PS, PSD) or a control group (C) of healthy matches. All trial groups received distinct anesthetic combinations during surgery, while controls mirrored patient criteria.Group P (propofol and remifentanil were maintained during the surgery), Group PS (propofol, remifentanil, and sevoflurane were maintained during the surgery), and Group PSD (propofol, remifentanil, sevoflurane, and dexmedetomidine were maintained during the surgery).All participants were rated using a series of cognitive assessment scales before and three days after surgery. All participants were interviewed over the telephone, 7 days, 30 days, and 90 days postoperatively.

RESULTS

POCD incidences in the PSD (combined anesthetization with propofol, sevoflurane, and dexmedetomidine) group was significantly lower than that in the PS (combined anesthetization with propofol and sevoflurane) group, 1 day post-surgery (10.0% vs. 40.0%, P = 0.008), and the results were consistent at 3 days post-surgery. When the patients were assessed 7 days, 30 days, and 90 days postoperatively, there was no significant difference in POCD incidence among the three groups. Multivariate logistic regression analysis of POCD one day after surgery showed that education level was negatively correlated with incidence of POCD (P = 0.018) and single lung ventilation time was positively correlated with incidence of POCD (P = 0.001).

CONCLUSION

For elderly patients who underwent a thoracic surgical procedure, dexmedetomidine sedation shows an obvious advantage on improving short-term POCD incidence, which is caused by sevoflurane.

Postoperative cognitive dysfunction: a concept analysis

BACKGROUND

Post-operative cognitive dysfunction (POCD) is a concern for clinicians that often presents post-surgery where generalized anesthesia has been used. Its prevalence ranges from 36.6% in young adults to 42.4% in older individuals. Conceptual clarity for POCD is lacking in the currently body literature. Our two-fold purpose of this concept analysis was to (1) critically appraise the various definitions, while also providing the best definition, of POCD and (2) narratively synthesize the attributes, surrogate or related terms, antecedents (risk factors), and consequences of the concept.

METHOD

The reporting of our review was guided by the PRISMA statement and the 6-step evolutionary approach to concept analysis developed by Rodgers. Three databases, including Medline, CINAHL, and Web of Science, were searched to retrieve relevant literature on the concept of POCD. Two independent reviewers conducted abstract and full-text screening, data extraction, and appraisal. The review process yielded a final set of 86 eligible articles.

RESULT

POCD was defined with varying severities ranging from subtle-to-extensive cognitive changes (1) affecting single or multiple cognitive domains that manifest following major surgery (2), is transient and reversible, and (3) may last for several weeks to years. The consequences of POCD may include impaired quality of life, resulting from withdrawal from the labor force, increased patients' dependencies, cognitive decline, an elevated risk of dementia, rising healthcare costs, and eventual mortality.

CONCLUSION

This review resulted in a refined definition and comprehensive analysis of POCD that can be useful to both researchers and clinicians. Future research is needed to refine the operational definitions of POCD so that they better represent the defining attributes of the concept.

Intraoperative use of processed electroencephalogram in a quaternary center: a quality improvement audit

Although intraoperative electroencephalography (EEG) is not consensual among anesthesiologists, growing evidence supports its use to titrate anesthetic drugs, assess the level of arousal/consciousness, and detect ischemic cerebrovascular events; in addition, intraoperative EEG monitoring may decrease the incidence of postoperative neurocognitive disorders. Based on the known and potential benefits of intraoperative EEG monitoring, an educational program dedicated to staff anesthesiologists, residents of Anesthesiology and anesthesia technicians was started at Cleveland Clinic Abu Dhabi in May 2022 and completed in June 2022, aiming to have all patients undergoing general anesthesia with adequate brain monitoring and following international initiatives promoting perioperative brain health. All the surgical cases performed under General Anesthesia at 24 daily locations were prospectively inspected during 15 consecutive working days in March 2023. The use or absence of a processed EEG monitor was registered. Of 379 surgical cases distributed by 24 locations under General Anesthesia, 233 cases (61%) had processed EEG monitoring. The specialty with the highest use of EEG monitoring was Cardiothoracic Surgery, with 100% of cases, followed by interventional Cardiology (90%) and Vascular Surgery (75%). Otorhinolaryngology (29%), Gastrointestinal Endoscopy (25%), and Interventional Pulmonology (20%) were the areas with the lowest use of EEG monitoring. Of note, in the Neuroradiology suite, no processed EEG monitor was used in cases under General Anesthesia. We identified a reasonable use of EEG monitoring during general anesthesia, unfortunately not reaching our target of 100%. The educational and support program previously implemented within the Anesthesiology Institute needs to be continued and improved, including workshops, online discussions, and journal club sessions, to increase the use of EEG monitoring in underused areas.

Delirium in acute stroke is associated with increased cognitive and psychiatric symptoms over time: The Nor-COAST study

BACKGROUND

Delirium, an acute and fluctuating mental disturbance of attention, cognition, and consciousness, commonly occurs in acute stroke. Research on long-term outcomes of stroke patients experiencing delirium is limited, especially regarding cognitive and psychiatric symptoms.

METHODS

As part of the Nor-COAST study, 373 patients were screened for delirium using the Confusion Assessment Method (CAM) in the acute phase of stroke. Patients were included in the mixed-model linear regression analyses if they had available data from the follow-ups at three, 18 or 36 months, totaling 334 (44.6 % women, mean (SD) age: 72.1 (12.5) years, 17 (5.1 %) diagnosed with delirium). Global cognition was measured using the Montreal Cognitive Assessment (MoCA). Psychiatric symptoms were measured using the Hospital Anxiety and Depression Scale (HADS) and the Neuropsychiatric Inventory-Questionnaire (NPI-Q).

RESULTS

At three months, delirium was associated with a higher NPI-Q score (Mean (SD) 2.9 (3.6) vs 1.4 (2.2)). At 18 and 36 months, delirium was associated with a lower MoCA score (Mean (SD) 19.7 (6.6) vs 24.3 (5.0), and 20.6 (7.6) vs 24.6 (4.8)), higher HADS anxiety symptoms (5.0 (4.3) vs 3.3 (3.3), and 5.9 (4.1) vs 3.4 (3.6)), higher HADS depression symptoms (7.2 (4.7) vs 3.4 (3.3), and 6.6 (5.1) vs 3.7 (3.7)), and higher NPI-Q score (2.4 (4.4) vs 1.7 (2.3), 2.6 (4.5) vs 1.0 (1.9)). Delirium significantly predicted the psychiatric symptoms hallucinations and agitation.

CONCLUSIONS

Patients with delirium in the acute phase of stroke may be particularly vulnerable to developing cognitive and psychiatric symptoms in the chronic phase.

Investigating the correlation of delirium after cardiac surgery with memories and posttraumatic stress disorder consequences of intensive care unit: A prospective cohort study

OBJECTIVES

To explore the differences in post-intensive care unit memory and posttraumatic stress disorder symptoms between patients with and without delirium, and assess the correlations between the two.

DESIGN

Prospective cohort observation study.

SETTING

A cardiac intensive care unit of a tertiary hospital in China. We enrolled 318 consecutive patients after cardiac surgery between December 2017 and March 2019.

MAIN OUTCOME MEASURES

Delirium was assessed using the Confusion Assessment Method for the ICU from intensive care unit admission to discharge. Intensive care unit memory was assessed using the ICU-Memory Tool through face-to-face interviews one week after discharge. Posttraumatic stress disorder was measured telephonically using the Impact of Events Scale-revised questionnaire at three months post-discharge.

RESULTS

Eighty patients each in the delirium and non-delirium groups were enrolled for follow-up interviews. Patients with delirium had vaguer memories of pre-intensive care unit admission and of their stay, and recollected more memories of feelings (vs. without delirium). Posttraumatic stress disorder was diagnosed in 14 patients with and in seven without delirium, with non-significant differences between groups. Delirium did not influence post-intensive care unit factual, feeling, and delusional memories, nor posttraumatic stress disorder and hyperarousal, intrusion, and avoidance. The memories of feelings were positively correlated with the last three (r = 0.285, r = 0.390 and r = 0.373, respectively).

CONCLUSION

Patients with delirium had vague intensive care unit memories. Memories of feelings were positively correlated with symptoms of hyperarousal, intrusion, and avoidance. Delirium did not influence factual, feeling, or delusional memories nor posttraumatic stress disorder incidence and symptoms.

IMPLICATIONS FOR CLINICAL PRACTICE

Interventions are needed to reduce the impact of vague memory in patients with post-intensive care unit delirium. Memories of feelings should be focused on because of their correlation with hyperarousal, intrusion, and avoidance. Delirium prevention and early recognition measures are suggested.

Global research and scientific publications on PND between 1969 and 2022: A bibliometric analysis

Objectives

We hope to offer a comprehensive understanding of the advancements and patterns in research on PND. Methods: We performed a thorough search on the Web of Science Core Collection to locate relevant studies published from 1969 to 2022 and utilized four distinct tools, namely VOSviewer (J Data Inf Sci, 2017, 2, 1; J Am Soc Inf Sci, 1973, 24, 265; Amer Doc, 1963, 14, 10 and Scientometrics, 2010, 82, 581), CiteSpace (Scientometrics, 2010, 84, 523), Scimago Graphica, and R-bibliometrix which allowed us to examine various aspects. Results: We included a total of 6787 articles and reviews for analysis which described PND research, the sources, and the subfields; highlighted the significant developments in this field; identified three main directions in PND.Conclusion: This study highlights the rapid growth of research on PND in recent years and provided an overview of previous studies in the field of PND, thereby establishing the overall landscape of PND research and identifying potential avenues for future investigations.

Methods

We performed a thorough search on the Web of Science Core Collection to locate relevant studies published from 1969 to 2022. To perform bibliometric analysis and network visualization, we utilized four distinct tools, namely VOSviewer (J Data Inf Sci, 2017, 2, 1; J Am Soc Inf Sci, 1973, 24, 265; Amer Doc, 1963, 14, 10 and Scientometrics, 2010, 82, 581), CiteSpace (Scientometrics, 2010, 84, 523), Scimago Graphica, and R-bibliometrix. These tools allowed us to examine various aspects, including the yearly publication output, the contribution of different countries or regions, the involvement of active journals, co-citation analysis, publication status, keywords, and terms, as well as scientific categories. We hope to offer a comprehensive understanding of the advancements and patterns in research on PND. The insights gained from this study can assist researchers and clinicians in enhancing the management and implementation of their work in this field.

Results

In this study, we included a total of 6787 articles and reviews for analysis. First, publication trends and contribution by country analysis described PND research. Second, a historical analysis described PND research, the sources, and the subfields. Third, an analysis of keywords highlighted the significant developments in this field. Fourth, an analysis of research themes identified three main directions in PND.

Conclusion

In summary, the research volume exhibits exponential growth over time. Furthermore, the majority of contributions originate from Western countries and China. The interdisciplinary nature of the field is evident, with its roots in biology and medicine and further branching into psychology and social sciences. POCD, delirium-predominant associated clinical management were major research themes about PND.

Immunological Analysis of Postoperative Delirium after Thoracic Aortic Surgery

Background

Delirium is a recognized neurological complication following cardiac surgery and is associated with adverse clinical outcomes, including elevated mortality and prolonged hospitalization. While several clinical risk factors for post-cardiac surgery delirium have been identified, the pathophysiology related to the immune response remains unexamined. This study was conducted to investigate the immunological factors contributing to delirium in patients after thoracic aortic surgery.

Methods

We retrospectively evaluated 43 consecutive patients who underwent thoracic aortic surgery between July 2017 and June 2018. These patients were categorized into 2 groups: those with delirium and those without it. All clinical characteristics were compared between groups. Blood samples were collected and tested on the day of admission, as well as on postoperative days 1, 3, 7, and 30. Levels of helper T cells (CD4), cytotoxic T cells (CD8), B cells (CD19), natural killer cells (CD56+CD16++), and monocytes (CD14+CD16-) were measured using flow cytometry.

Results

The median patient age was 71 years (interquartile range, 56.7 to 79.0 years), and 21 of the patients (48.8%) were male. Preoperatively, most immune cell counts did not differ significantly between groups. However, the patients with delirium exhibited significantly higher levels of interleukin-6 and lower levels of tumor necrosis factor-alpha (TNF-α) than those without delirium (p<0.05). Multivariate analysis revealed that lower TNF-α levels were associated with an increased risk of postoperative delirium (p<0.05).

Conclusion

Postoperative delirium may be linked to perioperative changes in immune cells and preoperative cytokine levels. Additional research is required to elucidate the pathophysiological mechanisms underlying delirium.

Dexmedetomidine alleviates sevoflurane-induced neuroinflammation and neurocognitive disorders by suppressing the P2X4R/NLRP3 pathway in aged mice

PURPOSE

Microglia-mediated inflammation is associated with perioperative neurocognitive disorders (PNDs) caused by sevoflurane. Dexmedetomidine has been reported to protect against sevoflurane-induced cognitive impairment. In this study, we investigated the effects and underlying mechanisms of dexmedetomidine on sevoflurane-induced microglial neuroinflammation and PNDs.

METHODS

Wild-type and purinergic ionotropic 4 receptor (P2X4R) overexpressing C57/BL6 mice were intraperitoneally injected with 20 μg/kg dexmedetomidine or an equal volume of normal saline 2 h prior to sevoflurane exposure. The Morris water maze (MWM) test was performed to assess cognitive function. Immunofluorescence staining was employed to detect microglial activation. The expression levels of proinflammatory cytokines were measured by real-time quantitative PCR (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA). The protein levels of P2X4R and NOD-like receptor protein 3 (NLRP3) were detected by Western Blotting.

RESULTS

Sevoflurane increased the number of microglia, upregulated the levels of proinflammatory cytokines, elevated the protein levels of P2X4R and NLRP3 in the hippocampus and induced cognitive decline, while pretreatment with dexmedetomidine downregulated the protein levels of P2X4R and NLRP3, alleviated sevoflurane-induced microglial neuroinflammation and improved cognitive dysfunction. Moreover, overexpression of P2X4R weakened the neuroprotective effect of dexmedetomidine.

CONCLUSIONS

Dexmedetomidine protected against sevoflurane-induced neuroinflammation and neurocognitive disorders by suppressing the P2X4R/NLRP3 pathway.

Cognitive and Cerebrospinal Fluid Alzheimer's Disease-related Biomarker Trajectories in Older Surgical Patients and Matched Nonsurgical Controls

BACKGROUND

Anesthesia and/or surgery accelerate Alzheimer's disease pathology and cause memory deficits in animal models, yet there is a lack of prospective data comparing cerebrospinal fluid (CSF) Alzheimer's disease-related biomarker and cognitive trajectories in older adults who underwent surgery versus those who have not. Thus, the objective here was to better understand whether anesthesia and/or surgery contribute to cognitive decline or an acceleration of Alzheimer's disease-related pathology in older adults.

METHODS

The authors enrolled 140 patients 60 yr or older undergoing major nonneurologic surgery and 51 nonsurgical controls via strata-based matching on age, sex, and years of education. CSF amyloid β (Aβ) 42, tau, and p-tau-181p levels and cognitive function were measured before and after surgery, and at the same time intervals in controls.

RESULTS

The groups were well matched on 25 of 31 baseline characteristics. There was no effect of group or interaction of group by time for baseline to 24-hr or 6-week postoperative changes in CSF Aβ, tau, or p-tau levels, or tau/Aβ or p-tau/Aβ ratios (Bonferroni P > 0.05 for all) and no difference between groups in these CSF markers at 1 yr (P > 0.05 for all). Nonsurgical controls did not differ from surgical patients in baseline cognition (mean difference, 0.19 [95% CI, -0.06 to 0.43]; P = 0.132), yet had greater cognitive decline than the surgical patients 1 yr later (β, -0.31 [95% CI, -0.45 to -0.17]; P < 0.001) even when controlling for baseline differences between groups. However, there was no difference between nonsurgical and surgical groups in 1-yr postoperative cognitive change in models that used imputation or inverse probability weighting for cognitive data to account for loss to follow up.

CONCLUSIONS

During a 1-yr time period, as compared to matched nonsurgical controls, the study found no evidence that older patients who underwent anesthesia and noncardiac, nonneurologic surgery had accelerated CSF Alzheimer's disease-related biomarker (tau, p-tau, and Aβ) changes or greater cognitive decline.

EDITOR’S PERSPECTIVE

An exploratory research report on brain mineralization in postoperative delirium and cognitive decline

Delirium is a severe postoperative complication associated with poor overall and especially neurocognitive prognosis. Altered brain mineralization is found in neurodegenerative disorders but has not been studied in postoperative delirium and postoperative cognitive decline. We hypothesized that mineralization-related hypointensity in susceptibility-weighted magnetic resonance imaging (SWI) is associated with postoperative delirium and cognitive decline. In an exploratory, hypothesis-generating study, we analysed a subsample of cognitively healthy patients ≥65 years who underwent SWI before (N = 65) and 3 months after surgery (N = 33). We measured relative SWI intensities in the basal ganglia, hippocampus and posterior basal forebrain cholinergic system (pBFCS). A post hoc analysis of two pBFCS subregions (Ch4, Ch4p) was conducted. Patients were screened for delirium until the seventh postoperative day. Cognitive testing was performed before and 3 months after surgery. Fourteen patients developed delirium. After adjustment for age, sex, preoperative cognition and region volume, only pBFCS hypointensity was associated with delirium (regression coefficient [90% CI]: B = -15.3 [-31.6; -0.8]). After adjustments for surgery duration, age, sex and region volume, perioperative change in relative SWI intensities of the pBFCS was associated with cognitive decline 3 months after surgery at a trend level (B = 6.8 [-0.9; 14.1]), which was probably driven by a stronger association in subregion Ch4p (B = 9.3 [2.3; 16.2]). Brain mineralization, particularly in the cerebral cholinergic system, could be a pathomechanism in postoperative delirium and cognitive decline. Evidence from our studies is limited because of the small sample and a SWI dataset unfit for iron quantification, and the analyses presented here should be considered exploratory.

Sleep and circadian biomarkers of postoperative delirium (SLEEP-POD): protocol for a prospective and observational cohort study

INTRODUCTION

Surgical patients over 70 experience postoperative delirium (POD) complications in up to 50% of procedures. Sleep/circadian disruption has emerged as a potential risk factor for POD in epidemiological studies. This protocol presents a single-site, prospective observational study designed to examine the relationship between sleep/circadian regulation and POD and how this association could be moderated or mediated by Alzheimer's disease (AD) pathology and genetic risk for AD.

METHODS AND ANALYSIS

Study staff members will screen for eligible patients (age ≥70) seeking joint replacement or spinal surgery at Massachusetts General Hospital (MGH). At the inclusion visit, patients will be asked a series of questionnaires related to sleep and cognition, conduct a four-lead ECG recording and be fitted for an actigraphy watch to wear for 7 days before surgery. Blood samples will be collected preoperatively and postoperatively and will be used to gather information about AD variant genes (APOE-ε4) and AD-related pathology (total and phosphorylated tau). Confusion Assessment Method-Scale and Montreal Cognitive Assessment will be completed twice daily for 3 days after surgery. Seven-day actigraphy assessments and Patient-Reported Outcomes Measurement Information System questionnaires will be performed 1, 3 and 12 months after surgery. Relevant patient clinical data will be monitored and recorded throughout the study.

ETHICS AND DISSEMINATION

This study is approved by the IRB at MGH, Boston, and it is registered with the US National Institutes of Health on ClinicalTrials.gov (NCT06052397). Plans for dissemination include conference presentations at a variety of scientific institutions. Results from this study are intended to be published in peer-reviewed journals. Relevant updates will be made available on ClinicalTrials.gov.

TRIAL REGISTRATION NUMBER

NCT06052397.

Insulin resistance and osteocalcin associate with the incidence and severity of postoperative delirium in elderly patients undergoing joint replacement

AIM

While insulin sensitivity plays an important role in maintaining glucose metabolic homeostasis and cognitive function, its impact on postoperative delirium (POD) remains unclear. This study aimed to investigate the association between POD and indicators of insulin sensitivity, including insulin resistance and osteocalcin.

METHODS

A total of 120 elderly patients undergoing joint replacement were recruited and divided into delirium and non-delirium groups. Plasma and cerebrospinal fluid (CSF) samples were collected for the analysis of biomarkers, including insulin, uncarboxylated osteocalcin (ucOC), total osteocalcin (tOC), and glucose. Insulin resistance was assessed through the homeostatic model assessment of insulin resistance (HOMA-IR).

MAIN RESULTS

Out of the total, 28 patients (23.3%) experienced POD within 5 days after surgery. Patients with delirium exhibited higher levels of preoperative HOMA-IR and ucOC in CSF and plasma, and of tOC in CSF (P = 0.028, P < 0.001, P = 0.005, P = 0.019). After adjusting for variables, including age, Mini-Mental State Examination score, surgical site and preoperative fracture, only preoperative ucOC in CSF and HOMA-IR were significantly linked to the incidence of delirium (OR = 5.940, P = 0.008; OR = 1.208, P = 0.046, respectively), both of which also correlated with the severity of delirium (P = 0.007, P < 0.001). Receiver operating curve analysis indicated that preoperative HOMA-IR and ucOC in CSF might partly predict POD (area under the curve [AUC] = 0.697, 95% confidence interval [CI] = 0.501-0.775, AUC = 0.745, 95% CI = 0.659-0.860).

CONCLUSIONS

We observed that preoperative elevated HOMA-IR and ucOC in CSF were associated with the incidence and severity of POD. While these preliminary results need confirmation, they suggest a potential involvement of insulin resistance and osteocalcin in the pathological mechanism of POD. Geriatr Gerontol Int 2024; 24: 421-429.

Structural disconnectivity in postoperative delirium: A perioperative two-center cohort study in older patients

BACKGROUND

Structural disconnectivity was found to precede dementia. Global white matter abnormalities might also be associated with postoperative delirium (POD).

METHODS

We recruited older patients (≥65 years) without dementia that were scheduled for major surgery. Diffusion kurtosis imaging metrics were obtained preoperatively, after 3 and 12 months postoperatively. We calculated fractional anisotropy (FA), mean diffusivity (MD), mean kurtosis (MK), and free water (FW). A structured and validated delirium assessment was performed twice daily.

RESULTS

Of 325 patients, 53 patients developed POD (16.3%). Preoperative global MD (standardized beta 0.27 [95% confidence interval [CI] 0.21-0.32] p < 0.001) was higher in patients with POD. Preoperative global MK (-0.07 [95% CI -0.11 to (-0.04)] p < 0.001) and FA (0.07 [95% CI -0.10 to (-0.04)] p < 0.001) were lower. When correcting for baseline diffusion, postoperative MD was lower after 3 months (0.05 [95% CI -0.08 to (-0.03)] p < 0.001; n = 183) and higher after 12 months (0.28 [95% CI 0.20-0.35] p < 0.001; n = 45) among patients with POD.

DISCUSSION

Preoperative structural disconnectivity was associated with POD. POD might lead to white matter depletion 3 and 12 months after surgery.

Cognitive trajectories after surgery: Guideline hints for assessment and treatment

Elderly patients who undergo major surgery (not-neurosurgical) under general anaesthesia frequently complain about cognitive difficulties, especially during the first weeks after surgical "trauma". Although recovery usually occurs within a month, about one out of four patients develops full-blown postoperative Neurocognitive disorders (NCD) which compromise quality of life or daily autonomy. Mild/Major NCD affect approximately 10% of patients from three months to one year after major surgery. Neuroinflammation has emerged to have a critical role in the postoperative NCDs pathogenesis, through microglial activation and the release of pro-inflammatory cytokines which increase blood-brain-barrier permeability, enhance movement of leukocytes into the central nervous system (CNS) and favour the neuronal damage. Moreover, pre-existing Mild Cognitive Impairment, alcohol or drugs consumption, depression and other factors, together with several intraoperative and post-operative sequelae, can exacerbate the severity and duration of NCDs. In this context it is crucial rely on current progresses in serum and CSF biomarker analysis to frame neuroinflammation levels, along with establishing standard protocol for neuropsychological assessment (with specific set of tools) and to apply cognitive training or neuromodulation techniques to reduce the incidence of postoperative NCDs when required. It is recommended to identify those patients who would need such preventive intervention early, by including them in pre-operative and post-operative comprehensive evaluation and prevent the development of a full-blown dementia after surgery. This contribution reports all the recent progresses in the NCDs diagnostic classification, pathogenesis discoveries and possible treatments, with the aim to systematize current evidences and provide guidelines for multidisciplinary care.

Butyrylcholinesterase activity in patients with postoperative delirium after cardiothoracic surgery or percutaneous valve replacement- an observational interdisciplinary cohort study

BACKGROUND AND OBJECTIVES

Postoperative delirium is a frequent and severe complication after cardiac surgery. Activity of butyrylcholinesterase (BChE) has been discussed controversially regarding a possible role in its development. This study aimed to investigate the relevance of BChE activity as a biomarker for postoperative delirium after cardiac surgery or percutaneous valve replacement.

METHODS

A total of 237 patients who received elective cardiothoracic surgery or percutaneous valve replacement at a tertiary care centre were admitted preoperatively. These patients were tested with the Montreal Cognitive Assessment investigating cognitive deficits, and assessed for postoperative delirium twice daily for three days via the 3D-CAM or the CAM-ICU, depending on their level of consciousness. BChE activity was measured at three defined time points before and after surgery.

RESULTS

Postoperative delirium occurred in 39.7% of patients (n = 94). Univariate analysis showed an association of pre- and postoperative BChE activity with its occurrence (p = 0.037, p = 0.001). There was no association of postoperative delirium and the decline in BChE activity (pre- to postoperative, p = 0.327). Multivariable analysis including either preoperative or postoperative BChE activity as well as age, MoCA, type 2 diabetes mellitus, coronary heart disease, type of surgery and intraoperative administration of red-cell concentrates was performed. Neither preoperative nor postoperative BChE activity was independently associated with the occurrence of postoperative delirium (p = 0.086, p = 0.484). Preoperative BChE activity was lower in older patients (B = -12.38 (95% CI: -21.94 to -2.83), p = 0.011), and in those with a history of stroke (B = -516.173 (95% CI: -893.927 to -138.420), p = 0.008) or alcohol abuse (B = -451.47 (95% CI: -868.38 to -34.55), p = 0.034). Lower postoperative BChE activity was independently associated with longer procedures (B = -461.90 (95% CI: -166.34 to -757.46), p = 0.002), use of cardiopulmonary bypass (B = -262.04 (95% CI: -485.68 to -38.39), p = 0.022), the number of administered red cell-concentrates (B = -40.99 (95% CI: -67.86 to -14.12), p = 0.003) and older age (B = -9.35 (95% CI: -16.04 to -2.66), p = 0.006).

CONCLUSION

BChE activity is not independently associated with the occurrence of postoperative delirium. Preoperative BChE values are related to patients' morbidity and vulnerability, while postoperative activities reflect the severity, length and complications of surgery.

Anesthesia and dementia: An up-to-date review of the existing literature

Concerns around the impact of anesthesia on cognitive decline and dementia, including Alzheimer's Disease (AD), have been increasing and recently attracting considerable attention in the research community. One unanswered question is whether anesthesia is a risk factor of dementia, specifically AD type dementia. A large body of evidence, coming from in vivo and in vitro models, suggests that exposure to anesthetic agents may increase the risk of AD through mechanisms of action similar to AD's neuropathology. In terms of clinical studies, our knowledge of the relationship between anesthesia and dementia is based on limited data, with most studies suggesting that there is no association. The aim of this paper was therefore to outline recent clinical studies exploring this controversial relationship and discuss future directions in terms of study design and potential areas of study. As the aging population and the prevalence of dementia and AD increases, we need a better understanding of anesthesia as a risk factor for neurodegeneration through well-designed studies. Despite the controversy, there seems to be little evidence to support that anesthesia itself or other surgical and patient factors can cause or accelerate AD.

Association Between Anesthetics and Postoperative Delirium in Elderly Patients Undergoing Spine Surgery: Propofol Versus Sevoflurane

STUDY DESIGNS

Retrospective Observational StudyObjectives: To compare the incidence of POD after propofol- and sevoflurane-based anesthesia in elderly patients undergoing spine surgery.

METHODS

In this study, the medical records of elderly patients ≥ 65 years of age who underwent spine surgery under total intravenous anesthesia with propofol or inhalational anesthesia with sevoflurane were reviewed. The primary outcome was the incidence of POD after propofol- and sevoflurane-based anesthesia. Secondary outcomes included postoperative 30-day complications, length of postoperative hospital stay, associations of patient characteristics, and surgery- and anesthesia-related data with the development of POD, and associations of anesthetics with clinical outcomes such as postoperative 30-day complications, and length of postoperative hospital stay.

RESULTS

Of the 281 patients, POD occurred in 29 patients (10.3%). POD occurred more frequently in the sevoflurane group than in the propofol group (15.7% vs. 5.0%, respectively; P=.003). The multivariable logistic regression analysis showed that sevoflurane-based anesthesia was associated with an increased risk of POD compared with propofol-based anesthesia (odds ratio [OR], 4.120; 95% confidence interval [CI], 1.549-10.954; P = .005), whereas anesthetics were not associated with postoperative 30-day complications and the length of postoperative hospital stay. Older age (OR, 1.242 CI, 1.130-1.366; P < .001) and higher mean pain score at postoperative day 1 (OR, 1.338 CI, 1.056-1.696; P = .016) were also associated with an increased risk of POD.

CONCLUSIONS

Propofol-based anesthesia was associated with a lower incidence of POD than sevoflurane-based anesthesia in elderly patients after spine surgery.

Risk factors for postoperative delirium in elderly patients undergoing heart valve surgery with cardiopulmonary bypass

BACKGROUND

The aim of this study was to identify the risk factors for postoperative delirium (POD) in elderly patients undergoing heart valve surgery with cardiopulmonary bypass (CPB).

METHODS

Elderly patients undergoing elective heart valve surgery with CPB in The First Affiliated Hospital of Wenzhou Medical University between March 2022 and March 2023 were selected for this investigation. They were divided into a POD group and a non-POD group. Their baseline information was collected and recorded, and the patients were subjected to neurocognitive function assessment using the Mini-Mental State Examination and the Montreal Cognitive Assessment scales before surgery. We also recorded their intraoperative indicators such as duration of surgery, duration of CPB, duration of aortic cross-clamp, blood transfusion, and postoperative indicators such as duration of mechanical ventilation, postoperative 24-hour drainage volume, and pain score. Regional cerebral oxygen saturation was monitored intraoperatively by near-infrared spectroscopy based INVOS5100C Regional Oximeter. Patients were assessed for the occurrence of POD using Confusion Assessment Method for the Intensive Care Unit, and logistic regression analysis of risk factors for POD was performed.

RESULTS

The study finally included 132 patients, with 47 patients in the POD group and 85 ones in the non-POD group. There were no significant differences in baseline information and preoperative indicators between the two groups. However, marked differences were identified in duration of surgery, duration of CPB, duration of aortic cross-clamp, duration of postoperative mechanical ventilation, postoperative length of stay in cardiac intensive care unit, postoperative length of hospital stay, intraoperative blood transfusion, postoperative pain score, and postoperative 24-hour drainage volume between the two groups (p < 0.05). Additionally, the two groups had significant differences in rScO2 at each intraoperative time point and in the difference of rScO2 from baseline at each intraoperative time point (p < 0.05). Multivariate logistic regression analysis showed that duration of surgery > 285 min (OR, 1.021 [95% CI, 1.008-1.035]; p = 0.002), duration of postoperative mechanical ventilation > 23.5 h (OR, 6.210 [95% CI, 1.619-23.815]; p = 0.008), and postoperative CCU stay > 3.5 d (OR, 3.927 [95% CI, 1.046-14.735]; p = 0.043) were independent risk factors of the occurrence of POD while change of rScO2 at T1>50.5 (OR, 0.832 [95% CI 0.736-0.941]; p = 0.003) was a protective factor for POD.

CONCLUSION

Duration of surgery duration of postoperative mechanical ventilation and postoperative CCU stay are risk factors for POD while change of rScO2 at T1 is a protective factor for POD in elderly patients undergoing heart valve surgery with CPB.

Role of Intraoperative Neuromonitoring to Predict Postoperative Delirium in Cardiovascular Surgery

OBJECTIVE

Postoperative delirium (POD) can occur in up to 50% of older patients undergoing cardiovascular surgery, resulting in hospitalization and significant morbidity and mortality. This study aimed to determine whether intraoperative neurophysiologic monitoring (IONM) modalities can be used to predict delirium in patients undergoing cardiovascular surgery.

DESIGN

Adult patients undergoing cardiovascular surgery with IONM between 2019 and 2021 were reviewed retrospectively. Delirium was assessed multiple times using the Intensive Care Delirium Screening Checklist (ICDSC). Patients with an ICDSC score ≥4 were considered to have POD. Significant IONM changes were evaluated based on a visual review of electroencephalography (EEG) and somatosensory evoked potentials data and documentation of significant changes during surgery.

SETTING

University of Pittsburgh Medical Center hospitals.

PARTICIPANTS

Patients 18 years old and older undergoing cardiovascular surgery with IONM monitoring.

MEASUREMENTS AND MAIN RESULTS

Of the 578 patients undergoing cardiovascular surgery with IONM, 126 had POD (21.8%). Significant IONM changes were noted in 134 patients, of whom 49 patients had delirium (36.6%). In contrast, 444 patients had no IONM changes during surgery, of whom 77 (17.3%) patients had POD. Upon multivariate analysis, IONM changes were associated with POD (odds ratio 2.12; 95% CI 1.31-3.44; p < 0.001). Additionally, baseline EEG abnormalities were associated with POD (p = 0.002).

CONCLUSION

Significant IONM changes are associated with an increased risk of POD in patients undergoing cardiovascular surgery. These findings offer a basis for future research and analysis of EEG and somatosensory evoked potential monitoring to predict, detect, and prevent POD.

The impact of perioperative stroke and delirium on outcomes after surgical aortic valve replacement

OBJECTIVE

The effects of stroke and delirium on postdischarge cognition and patient-centered health outcomes after surgical aortic valve replacement (SAVR) are not well characterized. Here, we assess the impact of postoperative stroke and delirium on these health outcomes in SAVR patients at 90 days.

METHODS

Patients (N = 383) undergoing SAVR (41% received concomitant coronary artery bypass graft) enrolled in a randomized trial of embolic protection devices underwent serial neurologic and delirium evaluations at postoperative days 1, 3, and 7 and magnetic resonance imaging at day 7. Outcomes included 90-day functional status, neurocognitive decline from presurgical baseline, and quality of life.

RESULTS

By postoperative day 7, 25 (6.6%) patients experienced clinical stroke and 103 (28.5%) manifested delirium. During index hospitalization, time to discharge was longer in patients experiencing stroke (hazard ratio, 0.62; 95% confidence interval [CI], 0.42-0.94; P = .02) and patients experiencing delirium (hazard ratio, 0.68; 95% CI, 0.54-0.86; P = .001). At day 90, patients experiencing stroke were more likely to have a modified Rankin score >2 (odds ratio [OR], 5.9; 95% CI, 1.7-20.1; P = .01), depression (OR, 5.3; 95% CI, 1.6-17.3; P = .006), a lower 12-Item Short Form Survey physical health score (adjusted mean difference -3.3 ± 1.9; P = .08), and neurocognitive decline (OR, 7.8; 95% CI, 2.3-26.4; P = .001). Delirium was associated with depression (OR, 2.2; 95% CI, 0.9-5.3; P = .08), lower 12-Item Short Form Survey physical health (adjusted mean difference -2.3 ± 1.1; P = .03), and neurocognitive decline (OR, 2.2; 95% CI, 1.2-4.0; P = .01).

CONCLUSIONS

Stroke and delirium occur more frequently after SAVR than is commonly recognized, and these events are associated with disability, depression, cognitive decline, and poorer quality of life at 90 days postoperatively. These findings support the need for new interventions to reduce these events and improve patient-centered outcomes.

Post-operative cognitive dysfunction is exacerbated by high-fat diet via TLR4 and prevented by dietary DHA supplementation

Post-operative cognitive dysfunction (POCD) is an abrupt decline in neurocognitive function arising shortly after surgery and persisting for weeks to months, increasing the risk of dementia diagnosis. Advanced age, obesity, and comorbidities linked to high-fat diet (HFD) consumption such as diabetes and hypertension have been identified as risk factors for POCD, although underlying mechanisms remain unclear. We have previously shown that surgery alone, or 3-days of HFD can each evoke sufficient neuroinflammation to cause memory deficits in aged, but not young rats. The aim of the present study was to determine if HFD consumption before surgery would potentiate and prolong the subsequent neuroinflammatory response and memory deficits, and if so, to determine the extent to which these effects depend on activation of the innate immune receptor TLR4, which both insults are known to stimulate. Young-adult (3mo) & aged (24mo) male F344xBN F1 rats were fed standard chow or HFD for 3-days immediately before sham surgery or laparotomy. In aged rats, the combination of HFD and surgery caused persistent deficits in contextual memory and cued-fear memory, though it was determined that HFD alone was sufficient to cause the long-lasting cued-fear memory deficits. In young adult rats, HFD + surgery caused only cued-fear memory deficits. Elevated proinflammatory gene expression in the hippocampus of both young and aged rats that received HFD + surgery persisted for at least 3-weeks after surgery. In a separate experiment, rats were administered the TLR4-specific antagonist, LPS-RS, immediately before HFD onset, which ameliorated the HFD + surgery-associated neuroinflammation and memory deficits. Similarly, dietary DHA supplementation for 4 weeks prior to HFD onset blunted the neuroinflammatory response to surgery and prevented development of persistent memory deficits. These results suggest that HFD 1) increases risk of persistent POCD-associated memory impairments following surgery in male rats in 2) a TLR4-dependent manner, which 3) can be targeted by DHA supplementation to mitigate development of persistent POCD.

Early postoperative neurocognitive complications in elderly patients: comparing those with and without preexisting mild cognitive impairment- a prospective study

BACKGROUND

As societies age, increasing numbers of older adults undergo surgeries with anesthesia. Postoperative delirium (POD) and postoperative cognitive dysfunction (POCD) frequently occur in older surgical patients. Most of these patients already have preoperative mild cognitive impairment (MCI). However, the correlation between MCI and POD remains unclear. This study aimed to determine the incidence of POD in elderly patients with and without preexisting MCI.

METHODS

A prospective study enrolled patients aged 60 years and above scheduled for major surgeries between December 2017 and April 2022. Preoperative MCI was determined by a Montreal Cognitive Assessment (MoCA) score between 18 and 24. POD was diagnosed using criteria from the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). POCD was characterized by a MoCA score reduction of 2 or more points from the preoperative score. The primary outcome was the incidence of POD within the first 72 h postoperatively. Secondary outcomes encompassed other postoperative complications, including POCD.

RESULTS

The study comprised 223 elderly patients with MCI and 56 without MCI. The incidence of POD was 16.6% in the MCI group and 14.3% in the non-MCI group (P = 0.839). POCD occurred in 24.3% of MCI patients and 50% of non-MCI patients (P = 0.001). There were no significant differences in other postoperative complications between the groups. Postoperatively, the MCI group notably declined in visuospatial, attention, and orientation domains, while the non-MCI group declined in all domains except delayed recall.

CONCLUSIONS

The incidence of POD was similar in the MCI and non-MCI groups. However, the non-MCI group demonstrated a higher incidence of POCD than the MCI group. This was identified by a reduction in postoperative MoCA scores for the visuospatial, naming, attention, language, abstraction, and orientation domains. These findings underscore the importance of postoperative cognitive assessments for both elderly patients with preexisting MCI and those with previously intact cognitive functions.

TRIAL REGISTRATION

This trial was retrospectively registered in the Thai Clinical Trials Registry on 15/01/2019 (registration number: TCTR20190115001).

Successful aging after elective surgery II: Study cohort description

BACKGROUND

The Successful Aging after Elective Surgery (SAGES) II Study was designed to examine the relationship between delirium and Alzheimer's disease and related dementias (AD/ADRD), by capturing novel fluid biomarkers, neuroimaging markers, and neurophysiological measurements. The goal of this paper is to provide the first complete description of the enrolled cohort, which details the baseline characteristics and data completion. We also describe the study modifications necessitated by the COVID-19 pandemic, and lay the foundation for future work using this cohort.

METHODS

SAGES II is a prospective observational cohort study of community-dwelling adults age 65 and older undergoing major non-cardiac surgery. Participants were assessed preoperatively, throughout hospitalization, and at 1, 2, 6, 12, and 18 months following discharge to assess cognitive and physical functioning. Since participants were enrolled throughout the COVID-19 pandemic, procedural modifications were designed to reduce missing data and allow for high data quality.

RESULTS

About 420 participants were enrolled with a mean (standard deviation) age of 73.4 (5.6) years, including 14% minority participants. Eighty-eight percent of participants had either total knee or hip replacements; the most common surgery was total knee replacement with 210 participants (50%). Despite the challenges posed by the COVID-19 pandemic, which required the use of novel procedures such as video assessments, there were minimal missing interviews during hospitalization and up to 1-month follow-up; nearly 90% of enrolled participants completed interviews through 6-month follow-up.

CONCLUSION

While there are many longitudinal studies of older adults, this study is unique in measuring health outcomes following surgery, along with risk factors for delirium through the application of novel biomarkers-including fluid (plasma and cerebrospinal fluid), imaging, and electrophysiological markers. This paper is the first to describe the characteristics of this unique cohort and the data collected, enabling future work using this novel and important resource.

Preoperative electroencephalographic alpha-power changes with eyes opening are associated with postoperative attention impairment and inattention-related delirium severity

BACKGROUND

In the eyes-closed, awake condition, EEG oscillatory power in the alpha band (7-13 Hz) dominates human spectral activity. With eyes open, however, EEG alpha power substantially decreases. Less alpha attenuation with eyes opening has been associated with inattention; thus, we analysed whether reduced preoperative alpha attenuation with eyes opening is associated with postoperative inattention, a delirium-defining feature.

METHODS

Preoperative awake 32-channel EEG was recorded with eyes open and eyes closed in 71 non-neurological, noncardiac surgery patients aged ≥ 60 years. Inattention and other delirium features were assessed before surgery and twice daily after surgery until discharge. Eyes-opening EEG alpha-attenuation magnitude was analysed for associations with postoperative inattention, primarily, and with delirium severity, secondarily, using multivariate age- and Mini-Mental Status Examination (MMSE)-adjusted logistic and proportional-odds regression analyses.

RESULTS

Preoperative alpha attenuation with eyes opening was inversely associated with postoperative inattention (odds ratio [OR] 0.73, 95% confidence interval [CI]: 0.57, 0.94; P=0.038). Sensitivity analyses showed an inverse relationship between alpha-attenuation magnitude and inattention chronicity, defined as 'never', 'newly', or 'chronically' inattentive (OR 0.76, 95% CI: 0.62, 0.93; P=0.019). In addition, preoperative alpha-attenuation magnitude was inversely associated with postoperative delirium severity (OR 0.79, 95% CI: 0.65, 0.95; P=0.040), predominantly as a result of the inattention feature.

CONCLUSIONS

Preoperative awake, resting, EEG alpha attenuation with eyes opening might represent a neural biomarker for risk of postoperative attentional impairment. Further, eyes-opening alpha attenuation could provide insight into the neural mechanisms underlying postoperative inattention risk.

Optimizing delirium care in the era of Age-Friendly Health System

Delirium is a significant geriatric condition associated with adverse clinical and economic outcomes. The cause of delirium is usually multifactorial, and person-centered multicomponent approaches for proper delirium management are required. In 2017, the John A. Hartford Foundation and the Institute for Healthcare Improvement (IHI) launched a national initiative, Age-Friendly Health System (AFHS), promoting the use of a framework called 4Ms (what matters, medication, mentation, and mobility). The 4Ms framework's primary goal is to provide comprehensive and practical person-centered care for older adults and it aligns with the core concepts of optimal delirium management. In this special article, we demonstrate how a traditional delirium prevention and management model can be assessed from the perspective of AFHS. An example is the crosswalk with the Hospital Elder Life Program (HELP) Core Interventions and the 4MS, which demonstrates alignment in delirium management. We also introduce useful tools to create an AFHS environment in delirium management. Although much has been written about delirium management, there is a need to identify the critical steps in advancing the overall delirium care in the context of the AFHS. In this article, we suggest future directions, including the need for more prospective and comprehensive research to assess the impact of AFHS on delirium care, the need for more innovative and sustainable education platforms, fundamental changes in the healthcare payment system for proper adoption of AFHS in any healthcare setting, and application of AFHS in the community for continuity of care for older adults with delirium.

Risk factors for dementia in older intensive care unit (ICU) survivors

INTRODUCTION

As the number of older intensive care unit (ICU) survivors grows, there is an urgent need to identify modifiable risk factors for post-ICU dementia.

METHODS

We performed a secondary data analysis of 3144 ICU patients ≥ 50 years of age without a history of dementia or severe mental illness who were screened as part of the Pharmacological Management of Delirium (PMD) study. Delirium was assessed using the Confusion Assessment Method for the ICU. Dementia was identified using International Classification of Diseases Ninth and Tenth revision codes for dementia or prescription of anti-dementia medication.

RESULTS

Average age (standard deviation) was 65.2 ± 9.5 years; 50.4% were female; and 37.3% were Black. Analyses identified stroke (adjusted hazard ratio [HR] 2.49; 95% confidence interval [CI: 1.52, 4.07], P < 0.001), and depression (adjusted HR 3.03; 95% CI [1.80, 5.10], P < 0.001) as post-ICU risk factors for dementia.

DISCUSSION

Future studies will need to examine whether interventions targeting post-ICU stroke and depression can lower dementia incidence in ICU survivors.

HIGHLIGHTS

Risk factors for post-intensive care unit (ICU) dementia were distinct from those of Alzheimer's disease. Cardiovascular risk factors were not associated with dementia in older ICU survivors. Post-ICU stroke was associated with a higher risk of dementia in older ICU survivors. Post-ICU depression was associated with a higher risk of dementia in older ICU survivors.

Biomarkers of neurodegeneration and neural injury as potential predictors for delirium

OBJECTIVES

Determine if biomarkers of Alzheimer's disease and neural injury may play a role in the prediction of delirium risk.

METHODS

In a cohort of older adults who underwent elective surgery, delirium case-no delirium control pairs (N = 70, or 35 matched pairs) were matched by age, sex and vascular comorbidities. Biomarkers from CSF and plasma samples collected prior to surgery, including amyloid beta (Aβ)42 , Aβ40 , total (t)-Tau, phosphorylated (p)-Tau181 , neurofilament-light (NfL), and glial fibrillary acid protein (GFAP) were measured in cerebrospinal fluid (CSF) and plasma using sandwich enzyme-linked immunosorbent assays (ELISAs) or ultrasensitive single molecule array (Simoa) immunoassays.

RESULTS

Plasma GFAP correlated significantly with CSF GFAP and both plasma and CSF GFAP values were nearly two-fold higher in delirium cases. The median paired difference between delirium case and control without delirium for plasma GFAP was not significant (p = 0.074) but higher levels were associated with a greater risk for delirium (odds ratio 1.52, 95% confidence interval 0.85, 2.72 per standard deviation increase in plasma GFAP concentration) in this small study. No matched pair differences or associations with delirium were observed for NfL, p-Tau 181, Aβ40 and Aβ42 .

CONCLUSIONS

These preliminary findings suggest that plasma GFAP, a marker of astroglial activation, may be worth further investigation as a predictive risk marker for delirium.

Exploring the Pathophysiology of Delirium: An Overview of Biomarker Studies, Animal Models, and Tissue-Engineered Models

Delirium is an acute brain disorder associated with disorganized thinking, difficulty focusing, and confusion that commonly follows major surgery, severe infection, and illness. Older patients are at high risk for developing delirium during hospitalization, which may contribute to increased morbidity, longer hospitalization, and increased risk of institutionalization following discharge. The pathophysiology underlying delirium remains poorly studied. This review delves into the findings from biomarker studies and animal models, and highlights the potential for tissue-engineered models of the brain in studying this condition. The aim is to bring together the existing knowledge in the field and provide insight into the future direction of delirium research.

Perioperative cognition in association with malnutrition and frailty: a narrative review

Postoperative delirium (POD) is a prevalent clinical entity characterized by reversible fluctuating altered mental status and cognitive impairment with acute and rapid onset a few days after major surgery. Postoperative cognitive decline (POCD) is a more permanent extension of POD characterized by prolonged global cognitive impairment for several months to years after surgery and anesthesia. Both syndromes have been shown to increase morbidity and mortality in postoperative patients making their multiple risk factors targets for optimization. In particular, nutrition imparts a significant and potentially reversible risk factor. Malnutrition and frailty have been linked as risk factors and predictive indicators for POD and less so for POCD. This review aims to outline the association between nutrition and perioperative cognitive outcomes as well as potential interventions such as prehabilitation.

Electroencephalographic Biomarkers, Cerebral Oximetry, and Postoperative Cognitive Function in Adult Noncardiac Surgical Patients: A Prospective Cohort Study

BACKGROUND

Perioperative neurocognitive disorders are a major public health issue, although there are no validated neurophysiologic biomarkers that predict cognitive function after surgery. This study tested the hypothesis that preoperative posterior electroencephalographic alpha power, alpha frontal-parietal connectivity, and cerebral oximetry would each correlate with postoperative neurocognitive function.

METHODS

This was a single-center, prospective, observational study of adult (older than 18 yr) male and female noncardiac surgery patients. Whole-scalp, 16-channel electroencephalography and cerebral oximetry were recorded in the preoperative, intraoperative, and immediate postoperative settings. The primary outcome was the mean postoperative T-score of three National Institutes of Health Toolbox Cognition tests-Flanker Inhibitory Control and Attention, List Sorting Working Memory, and Pattern Comparison Processing Speed. These tests were obtained at preoperative baseline and on the first two postoperative mornings. The lowest average score from the first two postoperative days was used for the primary analysis. Delirium was a secondary outcome (via 3-min Confusion Assessment Method) measured in the postanesthesia care unit and twice daily for the first 3 postoperative days. Last, patient-reported outcomes related to cognition and overall well-being were collected 3 months postdischarge.

RESULTS

Sixty-four participants were recruited with a median (interquartile range) age of 59 (48 to 66) yr. After adjustment for baseline cognitive function scores, no significant partial correlation (ρ) was detected between postoperative cognition scores and preoperative relative posterior alpha power (%; ρ = -0.03, P = 0.854), alpha frontal-parietal connectivity (via weight phase lag index; ρ = -0.10, P = 0.570, respectively), or preoperative cerebral oximetry (%; ρ = 0.21, P = 0.246). Only intraoperative frontal-parietal theta connectivity was associated with postoperative delirium (F[1,6,291] = 4.53, P = 0.034). No electroencephalographic or oximetry biomarkers were associated with cognitive or functional outcomes 3 months postdischarge.

CONCLUSIONS

Preoperative posterior alpha power, frontal-parietal connectivity, and cerebral oximetry were not associated with cognitive function after noncardiac surgery.

EDITOR’S PERSPECTIVE

Association between postoperative delirium and adverse outcomes in older surgical patients: A systematic review and meta-analysis

STUDY OBJECTIVE

To assess the incidence of postoperative delirium and its outcomes in older non-cardiac surgical patients.

DESIGN

A systematic review and meta-analysis with multiple databases searched from inception to February 22, 2022.

SETTING

Postoperative assessments.

PATIENTS

Non-cardiac and non-neurological surgical patients aged ≥60 years with and without postoperative delirium. Included studies must report ≥1 postoperative outcome. Studies with a small sample size (N < 100 subjects) were excluded.

MEASUREMENTS

Outcomes comprised the pooled incidence of postoperative delirium and its postoperative outcomes, including mortality, complications, unplanned intensive care unit admissions, length of stay, and non-home discharge. For dichotomous and continuous outcomes, OR and difference in means were computed, respectively, with a 95% CI.

MAIN RESULTS

Fifty-four studies (20,988 patients, 31 elective studies, 23 emergency studies) were included. The pooled incidence of postoperative delirium was 19% (95% CI: 16%, 23%) after elective surgery and 32% (95% CI: 25%, 39%) after emergency surgery. In elective surgery, postoperative delirium was associated with increased mortality at 1-month (OR: 6.60; 95% CI: 1.58, 27.66), 6-month (OR: 5.69; 95% CI: 2.33, 13.88), and 1-year (OR: 2.87; 95% CI: 1.63, 5.06). The odds of postoperative complications, unplanned intensive care unit admissions, prolonged length of hospital stay, and non-home discharge were also higher in delirium cases. In emergency surgery, patients with postoperative delirium had greater odds of mortality at 1-month (OR: 3.56; 95% CI: 1.77, 7.15), 6-month (OR: 2.60; 95% CI: 1.88, 3.61), and 1-year (OR: 2.30; 95% CI: 1.77, 3.00).

CONCLUSIONS

Postoperative delirium was associated with higher odds of mortality, postoperative complications, unplanned intensive care unit admissions, length of hospital stay, and non-home discharge. Prevention and perioperative management of delirium may optimize surgical outcomes.

Novel Mechanisms of Perioperative Neurocognitive Disorders: Ferroptosis and Pyroptosis

Perioperative neurocognitive disorders (PNDs) are some of the most common postoperative complications among the elderly and susceptible individuals, which significantly worsens the clinical outcome of patients. However, the prevention and treatment strategies of PNDs are difficult to determine and implement since the pathogenesis of PNDs is not well understood. The development of living organisms is associated with active and organized cell death, which is essential for maintaining the homeostasis of life. Ferroptosis is a programmed cell death (different from apoptosis and necrosis) mainly caused by an imbalance in the generation and degradation of intracellular lipid peroxides due to iron overload. Pyroptosis is an inflammatory cell death characterized by the creation of membrane holes mediated by the gasdermin (GSDM) family, followed by cell lysis and the release of pro-inflammatory cytokines. Ferroptosis and pyroptosis are involved in the pathogenesis of various central nervous system (CNS) diseases. Furthermore, ferroptosis and pyroptosis are closely associated with the occurrence and development of PNDs. This review summarizes the main regulatory mechanisms of ferroptosis and pyroptosis and the latest related to PNDs. Based on the available evidence, potential intervention strategies that can alleviate PNDs by inhibiting ferroptosis and pyroptosis have also been provided.

Towards a potent and rapidly reversible Dexmedetomidine-based general anesthetic

IN CONCLUSION

Our results suggest that Dex supplemented with a low dose of a second agent creates a potent anesthetic that is rapidly reversed by atipamezole and caffeine.

Aptamer-Based Proteomics Measuring Preoperative Cerebrospinal Fluid Protein Alterations Associated with Postoperative Delirium

Delirium is a common postoperative complication among older patients with many adverse outcomes. Due to a lack of validated biomarkers, prediction and monitoring of delirium by biological testing is not currently feasible. Circulating proteins in cerebrospinal fluid (CSF) may reflect biological processes causing delirium. Our goal was to discover and investigate candidate protein biomarkers in preoperative CSF that were associated with the development of postoperative delirium in older surgical patients. We employed a nested case-control study design coupled with high multiplex affinity proteomics analysis to measure 1305 proteins in preoperative CSF. Twenty-four matched delirium cases and non-delirium controls were selected from the Healthier Postoperative Recovery (HiPOR) cohort, and the associations between preoperative protein levels and postoperative delirium were assessed using t-test statistics with further analysis by systems biology to elucidate delirium pathophysiology. Proteomics analysis identified 32 proteins in preoperative CSF that significantly associate with delirium (t-test p < 0.05). Due to the limited sample size, these proteins did not remain significant by multiple hypothesis testing using the Benjamini-Hochberg correction and q-value method. Three algorithms were applied to separate delirium cases from non-delirium controls. Hierarchical clustering classified 40/48 case-control samples correctly, and principal components analysis separated 43/48. The receiver operating characteristic curve yielded an area under the curve [95% confidence interval] of 0.91 [0.80-0.97]. Systems biology analysis identified several key pathways associated with risk of delirium: inflammation, immune cell migration, apoptosis, angiogenesis, synaptic depression and neuronal cell death. Proteomics analysis of preoperative CSF identified 32 proteins that might discriminate individuals who subsequently develop postoperative delirium from matched control samples. These proteins are potential candidate biomarkers for delirium and may play a role in its pathophysiology.

Intraoperative suggestions to prevent postoperative delirium in patients undergoing transaortic valvular replacement: a randomized placebo-controlled trial

BACKGROUND

Postoperative delirium (POD) is a serious complication following anaesthesia and surgery and significantly influences postoperative outcome especially in the elderly population. Intraoperative music and positive suggestions influence postoperative outcomes by attenuating analgesic demand and increasing patient satisfaction.

AIMS

Here, we examined the effect of intraoperative music and positive suggestions on the development of POD in aged patients undergoing transcatheter aortic valve replacement (TAVR) procedure under general anaesthesia.

METHODS

For this randomized placebo-controlled study, eligible patients without cognitive deficit, indicated by a MMSE < 10 points, were anesthetized using remifentanil and sevoflurane. Anaesthetic depth was guide with bispectral index. An audiotape with positive suggestions was applied from a MP3 player via headphones. POD, pain and PONV was assessed. CAM-ICU and Nu-DESC were done twice daily for the first 5 days.

RESULTS

Of 140 patients 118 patients could be analysed (57 male, 80.6 ± 5.1 years). POD was diagnosed in 16 patients (12.7%). POD was significantly more often observed in male (12, 21.1%) than in female (4, 6.6%, p = 0.02) and in patients with a low MMSE (23.6 ± 4.5 vs. 26.8 ± 2.8, p = 0.001). Anaesthetic depth did not influence the incidence of POD. Intraoperative music and suggestions did not affect the rate of POD, pain, analgesic requirement or PONV.

DISCUSSION

In patients undergoing TAVR male sex and low MMSE scoring are associated with an increase in POD.

CONCLUSIONS

Intraoperative music and positive suggestions do not influence the incidence of POD in this patient group.

STUDY REGISTRATION

DRKS: 00024444, start of registration: 4.02.202, final registration: 17.09.2021.

Update on Perioperative Delirium

A strong association between frailty and in-hospital delirium in nonsurgical patients has been shown. Physical and cognitive frailties have been associated with decline and dysfunction in the frontal cognitive domains. Risk factors for frailty are similar to risk factors for postoperative delirium (POD). Frailty can be screened and diagnosed by various tools and instruments. Different anesthetic techniques have been studied to decrease the incidence of POD. However, no anesthetic technique has been conclusively proven to decrease the risk of POD. Patients with dementia develop delirium more often, and delirium is associated with accelerated cognitive decline.

Systemic inflammation, neuroinflammation and perioperative neurocognitive disorders

Perioperative neurocognitive disorder (PND) is a common disorder following anesthesia and surgery, especially in the elderly. The complex cellular and molecular processes are involved in PND, but the underlying pathogenesis of which remains inconclusive due to conflicting data. A growing body of evidence has been shown that perioperative systemic inflammation plays important roles in the development of PND. We reviewed the relevant literature retrieved by a search in the PubMed database (on July 20, 2023). The search terms used were "delirium", "post operative cognitive dysfunction", "perioperative neurocognitive disorder", "inflammation" and "systemic", alone and in combination. All articles identified were English-language, full-text papers. The ones cited in the review are those that make a substantial contribution to the knowledge about systemic inflammation and PNDs. The aim of this review is to bring together the latest evidence for the understanding of how perioperative systemic inflammation mediates neuroinflammation and brain injury, how the inflammation is regulated and how we can translate these findings into prevention and/or treatment for PND.

Pro-Con Debate: Judicious Benzodiazepine Administration for Preoperative Anxiolysis in Older Patients

In this Pro-Con commentary article, we discuss the risks and benefits of administering preoperative benzodiazepines to older patients to decrease preoperative anxiety. The Pro side first focuses on the critical importance of treating preoperative anxiety and that benzodiazepines are the best tool to achieve that goal. The competing argument presented by the Con side is that myriad options exist to treat preoperative anxiety without simultaneously increasing the risk for devastating complications such as postoperative delirium. Both sides call for more high-quality investigations to determine the most effective strategies for decreasing preoperative anxiety in older adults while improving outcomes and reducing morbidity.